There are 2 classes, yes, since this is just a cut from a long class. I need to paint at least 6 more graph from another ArrayList. But it won´t draw just a simple line.
Can anyone help me, how can I draw it with netbeans panel?

This is not really a NetBeans issue but a how to draw graphics in Swing issue, and I think that your best bet is to go to the Sun Java tutorials and check out the tutorials that cover this. There's a bit to learn, but it is all worthwhile.